1. Technical Field
The present invention relates to a thermometer and a temperature measurement method.
2. Related Art
In the related art, a number of biological information measurement devices for managing health are used at home. For example, users measure their blood pressure to regulate their salt intake or measure their blood sugar level to administer insulin. In this way, daily biological information is measured at a determined time to collect the trend of biological information. There is an increasing demand for collecting the trend of biological information. A body temperature which is fundamental vital information provides biological information such as health condition, basal metabolic condition, or mental condition. A thermometer is a measurement device frequently used in daily life due to its simplicity of measurement. However, since the thermometer involves a short period of a non-active state (resting state) as necessary, there is few measurement device (product) which is frequently used and which is capable of measuring temperatures constantly even during activities. The invention relates to a core body thermometer which is capable of collecting a daily trend and which improves accuracy by correcting sensor mounting accuracy through calculation.
When it is necessary to know the internal temperature of a furnace or a pipeline, it may be desirable to measure the internal temperature indirectly from the outside without cutting the facility to install a thermometer and without a possibility of deterioration due to corrosion of the thermometer by the internal substance. Moreover, when it is necessary to know the health condition, basal metabolic condition, or mental condition from the body temperature of animals, temperature information of the core portion rather than the temperature of a surface layer portion is needed. In such a case, it is desirable to know the internal temperature via the surface layer portion. A biometric device is known as a heat flux compensation-type core body thermometer. However, this type of thermometer uses a heater in order to achieve temperature equilibrium between a temperature sensing probe and the core portion and thus consumes a large amount of power. Moreover, such a thermometer is too bulky and lacks portability. In the related art, there is a thermometer which is a non-heating type core body thermometer and which is capable of obtaining a core body temperature from unknown thermal resistance values of a temperature detection unit and the skin (for example, see JP-A-2006-308538). This thermometer uses a technique in which heat insulating materials on the surface attached to a measurement surface have the same thermal resistance, and a heat flux difference is given to the opposite side of the measurement surface, thus calculating the internal temperature. According to this technique, it is possible to measure the internal temperature based on only temperature information even when the thermal resistance values of the associated materials are unknown.
However, the thermometer disclosed in JP-A-2006-308538 has a possibility that satisfactory accuracy is not obtained due to mounting position offsets of the temperature detection unit.